1) Drop the mag
2) Rack the slide numerous times to make sure it is not loaded.
3) Lock back slide and visually and physically make sure the gun is not loaded
4) Release slide
5) Point gun in safe direction
6) Fire
7) Your striker fired weapon is now uncocked - although I am a bit confused as to why you need to do it. Long-term storage concerns?

"I personally think we developed language because of our deep inner need to complain."--Jane Wagner
"The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom."
-Isaac Asimov

Most of the strker-fired guns are not cocked in the first place. It's the rearward movement of the trigger that cocks, then fires, the pistol. This is one reason why most do not have a de-cocker - there is no need to de-cock in the first place.

I cannot say for certain if your pistol is like a Glock, or more like and XD in the way it's mechanism works.

The sigma is Very "Glock Like" in it's design and function. The one glaring difference is you can feel in a Glock trigger when the trigger is close to releasing the firing pin and with a Sigma is it the same tension until it fires. Especially if you do the striker spring replacement. It was my only beef with the weapon was you didn't know when the trigger was close to releasing the striker unless you were used to firing the weapon. With a Glock you can feel it a lot more.

I have a Sigma and it's a fantastic self defense weapon. Does everything it's made to do, every time, without a hiccup. Long, hard trigger = no Plaxico discharges and nobody will notice the 10# trigger if SHTF!